Rustbuster Custom Epoxy Primer 421

The 1.25L kit covers approx 10m² and includes 800ml of Component A, 200ml of Component B, and 250ml of thinner.
The 2.5L kit covers approx 20m² and includes 1.6L of Component A, 400ml of Component B, and 500ml of thinner.
The 6L kit covers approx 50m² and includes 4L of Component A, 1L of Component B, and 1L of thinner.

Primes Steel, Aluminium and GRP

Most primers for car bodywork are designed to adhere well and be easy to sand to a good finish.  When used in a controlled body shop environment with little change in temperature or humidity, they work very well.  But most auto restorations can take several years to complete and the luxury of a temperature controlled body shop are rarely available to the home restorer.

With exactly this scenario in mind Rustbuster have introduced a new totally non-porous body primer, Rustbuster Custom 421 body primer.  This means that all of your good preparation work can be preserved under a totally non porous layer of epoxy.  The car can be left in primer for the duration of the restoration without fear of rust appearing within the primers pores, or even perhaps more importantly absorbing moisture that is later going to burst out of your paintwork in micro blisters.

When the car is ready to paint just rub down the primer with p280-p320 abrasive.  You can apply polyester fillers either before application of Rustbuster Custom 421 or the filler can be sandwiched between two layers of

Epoxy.  Rustbuster Custom 421 is compatible with all of Rustbuster surface preparation products.  Rustbuster Custom 421 can be overpainted with single or two-pack top coats.  Rustbuster Custom 421 can be used as a holding primer for application after blast cleaning.  Custom 421 is fully compatible with Rustbuster Epoxy Mastic 121, and can be used either before or after application of Rustbuster Epoxy Mastic 121.

Recommended System (where to use)

Rustbuster Custom 421 can be used on steel, aluminium and GRP making it the ideal choice for auto bodywork.  We recommend the use of Rustbuster Epoxy Mastic 121 to the vehicle underside and suspension components due to its high film build.  Rustbuster Custom 421 is best used on the bodywork and top sides where a superb custom finish is achievable.

Drying/Cure Times

At 23 degrees C surface dry in 60 minutes.  Hard dry 6.5 hours.  Re-coat minimum 4 hours.  Lower temperatures will retard drying times.  Higher temperatures will improve the drying/cure times.  Flash until matt between costs.     Mixing: 4 part compound A to one part compound B,  thinners as required.

Previously Painted

Clean original paint surfaces to be painted with Rustbuster SP10 and water, rinse and wipe dry.  Degrease all repair areas with a silicone remover.  Apply to the area using a spray atomiser or lint free cloth.  Wipe dry the silicone remover with another lint free cloth.  Dry sand with p280-p320.  Sand bare areas with grey Scotchbrite and silicone remover.  Wipe off/dry any excess silicone remover with a lint free cloth.  Wipe dry and tack wipes before priming.